Conventionally, a power semiconductor module is known which includes: a circuit board comprising a metal base plate, a high thermal conduction insulation layer, and a wiring pattern; a semiconductor device for power joined to an element mount section of the wiring pattern; a cylindrical external terminal connection body that is installed in the wiring pattern electrically connected to the semiconductor device for power and to which an external terminal is inserted and connected; a through hole that is formed on the metal base plate and fixes a cooling fin mounted to a surface at the other side of the metal base plate to the metal base plate by a mount member; and a transfer mold resin body sealed to cover one side and a side face of the metal base plate, and the semiconductor device for power while a surface at the other side of the metal base plate and an upper portion of the cylindrical external terminal connection body are exposed, and an insertion hole section of the mount member communicating with the through hole and having a diameter larger than that of the through hole is formed.
[Patent Document 1] Japanese Patent